Blind stitch sewing machine



Feb. 6, 1940.

C. W. MUELLER BLIND STITCH SEWING MACHINE Filed Oct. 1, 1958 4 Sheets-Sheet 1 INVENTOR C/meu's M Mafia-7e ATTORN EY 1940- c. w. MUELLER BLIND STITCH SEWING MACHINE Filed Oct. 1, 1938 4 Sheets-Sheet 2 Feb. 6, 1940.

C. W. MUELLER BLIND STITCH SEWING MACHINE Filed Oct. 1, 1938 4 Sheets-Sheet 3 INVENTOR Can/e155 fi/fiyfzzfe ZZaam ATTORNEY 4 Sheets-Sheet 4 INVENTOR CHARLES W. MUELLER ATTORNEY C. W. MUELLER BLIND STITCH SEWING MACHINE Filed Oct. 1, 1938 Feb. 6, 1940.

Patented Feb. 6, 1940 PATENT" OFFICE BLIND STITCH SEWING MACHINE Charles W. Mueller, St. Louis, Mo., assignor to Lewis Invisible Stitch Machine Company, a corporation of Maine 1 1 Application October 1,

9 Claims.

"5. on the fair side of either piece of cloth, or in the case of relatively thin material appear as spaced dots, on the exposed or fair sides of the material sewn together.

While such a machine has numerous uses, it 'is particularly suitable for performing the operation known to the trade as the bluff edge. Inthis operation the facing of a coat is sewn to the body of the coat. In the finished garment one side of both the facing and the body of the coat is visible. It is, therefore, necessary that the stitches by which the facing is sewn to the body of the coat do not penetrate through either the body of the coat or the facing. Such an operation and others comparable thereto have heretofore been performed on large, doublethread or lock-stitch machines in which the body of the fabric and a node of the facing into the path of the needle. In such machines, as they have been operated, it is impossible to sew the two pieces of material together along a line a substantial distance from the edge or fold of :the material.

Heretofore, attempts have been'made to construct a machine for performing such operations without this limitation and adaptable to high speed operation, comparable to the small, highspeed, chain-stitch machines. Such attempts have not, however, been entirely successful, as the machines of this type, heretofore constructed, have not been entirely satisfactory to the cloth ing industry. It is a purpose and object of this invention to provide a machine of this type in which two pieces of cloth, or the two sections of a folded piece of cloth, may be sewn together with a blind stitch at any distance from the edge and which is'adapted for high speed operation either as a chain-stitch or a lock-stitch machine. In accordance with the invention there is provided a blind-stitch sewing machine having the usual stitch forming mechanism including a presser foot having an opening therethrough and a needle mounted for movement across the opening through the presser foot. Node-forming mechanism is provided for projecting the material through the opening in the presser foot and into the path of the needle. This mechanism includes two node-forming elements and an adjustable support therefor. One of the node-forming elements is mounted in a fixed relation to the path of the needle with respect to the position of the support relative to the needle. The other node-forming element is adjustably mounted for 1938, Serial No. 232,775 (Cl. 112178) adjustment with respect to the needle and relative to the support. This arrangement permits the independent regulation of the two nodes in their relation to the path of the needle, one being regulated through mechanism on one side of the presser foot and the other being regulated from the other side of the presser foot.

The node-forming mechanism and needle mounting of such a machine, embodying the invention, are illustrated in the accompanying drawings. The operating mechanism for the sewing machine has not been illustrated as operating mechanism of well known construction may be utilized.

In the drawings:

Fig. 1 is an end elevation of the pertinent part of the sewing machine;

Fig. 2 is a front elevation of the same;

Fig. 3 is an enlarged, sectional plan taken on the line 33 of Fig. 2;

Fig. 4 is an enlarged, sectional elevation taken on the line 4-4 of Fig, 1; J

Fig. 5 is an enlarged, sectional, end elevation taken on the irregular line 5-5 of Fig. 3; Y

Fig. 6 is an enlarged, fragmentary, sectional elevation taken on the line 66 ofFig. 3;

Fig. '7 is a plan of a piece of cloth sewn on the machine and illustrating the stitch;

Fig. 8 is a front elevation of a modified'form of the machine; and

Fig. 9 in a front, enlarged, sectional elevation of the same. a

The parts of a chain-stitch, blind-stitch, sewing machine necessary to properly illustrate the novel features of the invention have been shown in the drawings. These parts include a curved needle I secured in an arm 2 that is fastened on to the projecting end of an oscillatory shaft 3. The shaft 3 extends through an arm '4 that projects towards the operator of the machine 4 and for this reason commonly designated as, a forwardly extendingarm. The needle traverses, during each reciprocation or oscillation thereof, an opening a in a presser foot 5. The presser foot is secured to the arm 4 by depending brackets 6a and 6b one secured on each side of the arm 4 and to the corresponding sides of the presser foot. The presser foot has formed therein an arcuate needle guide 1 for guiding the needle in a fixed path across the presser foot. A looper 8, in the usual manner, picksup the loop formed at the beginning of the return stroke of the needle and presents the loop so that the needle passes therethrough before re-entering the material being sewn on the next succeeding stroke.

A top feed dog 9 having cloth-engaging teeth is provided for advancing the cloth through the machine. This feed dog operates in a well known manner to advance the cloth during the time the needle leaves and fe-enters the cloth. The

feed dog works against resiliently mounted work supports or platens I0 and II, one on each side of the opening through the presser foot. These platens serve to resiliently clamp the work against the side of the presser foot opposite the side over which the needle operates, that is, the under side of the presser foot in the machine illustrated. The top feed dog 9 has a compound motion by virtue of which at the start of its feeding action it presses down the work supportting platens and thus relieves the clamping forces, leaving the cloth free to move toward the rear of the machine with the feed dog.

All of the foregoing parts, with the exception of certain constructional features of the presser foot, interrelated as described are common and well known in blind-stitch, chain-stitch, sewing machines. Such parts, together with mechanism for effecting their cyclic operation in proper timed relation, are illustrated, for example, in Patent No. 1,905,391, issued April 25, 1933. This patent also illustrates mechanism suitable for operating the shaft through which the nodeforming mechanism hereinafter described is oscillated.

In the machine illustrated in the drawings, an oscillatory shaft I 2 is mounted, suitably journaled in bearings provided therefor, in a Work table (not shown). An extension I3 of the work table extends under the presser foot and carries the platens above described. The extension I3 has a yoke I4, extending from the end thereof, through an arm I5 of which there is threaded a centering screw 16. The conical end of the centering screw enters the centering bore in the end of the shaft I2 and forms a bearing therefor. A check-nut I7 holds the centering screw in the adjusted position. The work table is mounted so that it may move toward and away from the presser foot, 1. e. toward and away from the path of the needle. It is, however, resiliently urged towards the presser foot and its position with respect to the presser foot may be adjusted. A suitable work table and mounting therefor is illustrated in Patent No. 1,905,391, issued April 25, 1933.

At a point IZa below the presser foot, the shaft I2 is reduced in diameter, a shoulder being formed at the point of reduction. To the reduced portion of the shaft, the node-forming mechanism is connected for operation thereby. The nodeforming mechanism selves to project two nodes of material through the opening in the presser foot and into the path of the needle. Two nodeforming elements I8 and I9 are, therefore, included in the node forming mechanism. One of these, that to which the numeral I8 is applied, is connected to the shaft I2 such as to have a fixed relation to the path of the needle relative to the position of the shaft with respect to the path of the needle. The other node-forming element, that to which the numeral I9 is applied, is so mounted that it may move relative to the element I8 such that its relation to the path of the needle may vary independently of the shaft I2 and of the node-forming element I8.

In the construction illustrated, the nodeforming element I8 consists of a segment of a disk having an opening therethrough through which the reduced end I2a of the shaft I2 extends, and having a hub I8a which receives the adjacent end of the section of the shaft of larger diameter. The disk I8 is firmly secured to the shaft I2 for rotation therewith and the close fit of the disk on the shaft prevents any movement of the disk transverse to the axis of the shaft. The relation of the periphery of the disk is thus fixed relative to the path of the needle in respect to the position of the shaft I2 relative to the path of the needle.

The node-forming element IS in the machine illustrated is likewise a segment of a disk of slightly more than a semicircle. It is mounted upon a hub 20 secured on the section I2a of the shaft I2. The hub 20 has a flange 20a that abuts against the disk I8. Disk I3 is thus held against movement longitudinally of the shaft between the shoulder on the shaft and the flange 20a of the hub 26. The hub 20 is rectangular in shape and the disk I9 is provided with an elongated slot I941 in which the rectangular hub is received. The slot I90, is substantially longer in one direction than the thickness of the hub. The disk may therefore move transversely of the shaft and its relation to the path of the needle may 2,0

vary independently of the position of the shaft l2. The disk I9 is held in position on the hub 20 by a plate 2| fastened to the end of the hub by a machine screw 22. A collar 23 secured to the section I2a. of the shaft I2 holds the fore- 2 55 going assembly against movement longitudinally of the shaft.

The shaft I2 is oscillated about its axis by mechanism Well known in the art. It may be oscillated uniformly by mechanism such as that illustrated in Patent No. 1,905,391, issued April 25, 1933. Likewise, it may, for certain purposes, be differentially oscillated by mechanism such as that illustrated in Patent No. 1,989,602, issued January 29, 1935, for the purpose of producing stitches of different penetration or alternate skip and anchor stitches. In any event, the shaft is oscillated in timed relation with respect to the reciprocations of the needle. The shaft I2 and the disks I8 and I 9 make one complete oscillation for each reciprocation of the needle and the disks move in the direction of the feed during the feeding action of the feed dog 9.

The disk I 9 is resiliently urged in the direction of greater length of the slot I9a and towards the path of the needle. For this purpose there is provided a roller 24 rotatably mounted between the arms of a bifurcated piston element 25. The piston is slidably mounted in a housing 26 containing a spring 21. The spring 2! acts between the end of the piston element 25 and a cap 28 threaded into the end of the housing. A rod 29 extends from the piston element and through a central bore in the cap 28. The end of the rod 29 is threaded and a nut 30 and check nut 3I threaded on the rod form an adjustable limit stop to limit the movement of the piston element under the action of the spring 2'1. The roller 24 bears against the periphery of the disk I9 and the force exerted on the disk may be adjusted by adjusting the position of the cap 28. It is to be noted that the roller 24 is of such width that it may engage both disks I8 and I 9. By this arrangement, the disk I9 cannot come nearer the path of the needle than the disk I 8 and this determines the point or position from which the disk I9 yields under ordinary conditions. The nuts 30 and 3| may, however, be so adjusted as to make this point or position of yield lower.

Above the disk I8 there is a resilient work retaining clamp 32. This work retaining clamp consists of a piece of relatively thin resilient metal shaped as shown in Fig. 3 and having a bifurcated end, the arms 32a and 32b of which are turned into cylinders and journaled on a stud A 2,189,433 'S3uiThestud33 is threaded into the end of a rod 34 that extends into a hollow bushing 35 having a slotted head 35a. The bushing 35 is journaled in a bracket 36 and has a longitudinal slot in which one end 31a of a coiled spring 31 is received. Iihe other end 31b of the spring 37 bears upon the work retaining clamp. A set screw 38 holds the parts in position and the spring 31 is wound so as to place a resilient force on the work retaining clamp. This force may be varied by adjusting the bushing 36.

Above the disk l9 there isa rigid crown. This crown is in the form of a bell crank lever 39 shaped as shown in Figs. 3 and 5. The lever is pivoted on a stud 40 extending from a bracket 4| on the presser foot. One arm 39a of the lever extends over the disk [9 and the other arm 3% has formed integral therewith a lateral, internally threaded bushing 42. Threaded in the bushing, there is a set screw 43 having a head 43a the periphery of which is ribbed. The set screw abuts against a stop 44 formed as a part of the bracket 4!. Through this screw the position of the crown and thus the relation of the disk l9 to the path of the needle is determined as the crown acts against the force of the spring 2! and it is of sufiicient rigidity to overcome the force of the spring. The crown is held in adjusted position by a resilient detent 45 secured on the bushing 42 and engaging between the ribs in the head 43a of the set screw 43. i

In the modification illustrated in Figs. 8 and 9 of the drawings, the fixed and yieldable nodeforming disks are interchanged in position. The fixedly mounted disk I8 is to the left when viewed as in 'Figs. 8 and 9 and the yieldably mounted disk I9 is to the right. The fixedly mounted disk I8 has formed thereon a hub l8'a that is secured to the shaft I2 for rotation therewith. The yieldably mounted disk I9 is mounted upon a hub 20, secured to the shaft and having a rectangular section 20a that is received in the elongated slot in the disk IS. A flange Zllfb on the hub separates the fixed and yieldable disks and a plate 22 holds the disk l9 against movement longitudinally of the shaft, the plate 22 having an opening to receive the hub and being secured to the flange 2ll'b by machine screws as shown. With the exception of the fact that the rigid crown 39' and. the yieldable work retaining clamp 32' are interchanged in position-on the presser foot so that the crown is over the yieldable disk and the work retaining clamp is over the fixedly mounted disk, the remainder of the mechanism is the same as that shown in Figs. 1 to '7 and described above. I

From the foregoing description of the mechanism illustrated in the drawings, it will be apparent that the relation of the node formed in the material by the disk I8, with respect to the needle, is determined by the position of the shaft 12 relative to the path of the needle. The pene tration of the material in so far as the disk It! is concerned is, therefore, determined by the adjustment of the support I3 in which the shaft I2 is journaled below the plane of the presser foot. On the other hand, the relation of the node formed in the material by the disk ill with respect to the needle, and, therefore, the penetration, is determined by the adjustment of the crown, There is thus provided two spaced nodeforming elements one of which has a fixed rela-' tion to the path of the needle relative to the po-. sition of the shaft l2 and the other of which is yieldably mounted and its relation to the path of the j needle is determined by the regulating crown above the'presser foot.

In sewing the body of a garment to the facing in an operation to make the so-called bluff edge, the body 46 of the garment is folded back upon itself at any desired distance from the edge 46a. The reverse fold 46b in the body of the garment lies on top of the facing 41. So arranged the garment is entered in the machine, a fold guide 48 (Fig. 3) being adjusted to engage the edge 46a between the body and the facing and an edge guide 49 being positioned so that when the edge of the reverse fold in the body of the fabric engages the edge guide, the" fabric bears the relation to the node-forming disks as illustrated in the drawings. The reverse bend in the body of the fabric comes over the disk l9 and the facing comes over the disk I8. The suport or work table I3 in which the shaft I2 is journaled ,is adjusted to obtain the desired penetration in '7 and such that while the body and facing are securely sewn together at the line of stitching,

. the stitches are not Visible either through the facing or the body of the garment.

It Will be obvious that the machine illustrated may serve many purposes besides forming the so-called blufi edge operation; it may be used as a plain blind stitch machine or as a skipstitch machine and additional operations bringing into play the double node-forming arrangement may be performed on the machine. Likewise, it is obvious that various changes may be made by those skilled in the art in the details of the embodiment of the invention illustrated in the drawings and described above within the principle and scope of the invention as expressed in the appended claims.

, I claim:

1. In a sewing machine of the type described, the combination comprising a presser foot having an opening therethrough, a needle mounted for movement across the opening through the presser foot, node-forming mechanism including a pair of node-forming elements for projecting the material operated upon through the opening in the presser foot and into the path of the needle, means on one side of the presser foot for determining the relation of one of said node-forming elements with respect to the path of the needle, and means on the other-side of the presser-foot for determining the relation of the other node forming element with respect to the path of the needle.

2. In a sewing machine of the type described, the combination comprising a presser foot hav-- ing an opening therethrough, a needle mounted for movement across the opening through the presser foot, node-forming means including a pair of node-forming elements for projecting the material operated upon through the opening in the presser foot and into the path of the needle, one of said node-forming elements being yieldably mounted, and means for controlling the relation of the yieldable node-forming element with respect to the path of the needle including resilient means yieldably urging the said element toward the path of the needle.

3. In a sewing machine of the type described, the combination comprising a presser foot having an opening therethrough, a needle mounted for. movement across the opening through the presser ,foot, and node-forming mechanism for projecting a pair of nodes of the material operated upon through the opening in the presser foot and into the path of the needle including two node-forming element one of which is mounted for movement relative to the other and transverse to the path of the needle, yieldable means urging said movably mounted node-forming element toward the path of the needle, and means for regulating the relation of the node formed by said yieldable node-forming element with respect to the path of the needle including a regulating element positioned to oppose said yieldable means.

4. In a sewing machine of the type described, the combination comprising a presser foot having an opening therethrough, a needle mounted for movement across the opening through the presser foot, and node-forming mechanism for projecting a pair of nodes of the material operated upon through the opening in the presser foot and into the path of the needle including a movably mounted support mounted for movement toward and away from the path of the needle, a shaft carried by said support, two nodeforming elements operatively connected to said shaft for operation thereby, one of said nodeforming elements being connected to the shaft to have a fixed relation to the path of the needle in relation to the position of the shaft and the other of said node-forming elements being mounted for relative movement with respect to said fixedly mounted node-forming element and susbtantially transverse to the path of the needle, yieldable means urging said movably mounted node-forming element towards the path of the needle, and means for regulating the relation of the node formed by said yieldable node-forming element with respect to the path of the needle including a regulating element positioned to oppose said yieldable means.

5. In a sewing machine of the type described, the combination comprising a presser foot having an opening therethrough, a needle mounted for movement across the opening through the presser foot, and node-forming mechanism for projecting a pair of nodes of the material operated upon through the opening in the presser foot and into the path of the needle including a movably mounted support, mounted for movement toward and away from the path of the needle, a rotatably mounted shaft carried by said support, two node-forming elements operatively connected to said shaft for operation thereby, one of said node-forming elements being connected to the shaft to have a fixed relation to the path of the needle relative to the position of the shaft and the other of said node-forming elements being mounted for relative movement with respect to said fixedly mounted node-forming element and substantially transverse to the path of the needle, yieldable means urging said movably mounted node-forming element towards the path of the needle, and an adjustable crown for regulating the relation of the node of material formed by said yieldable node-forming element with respect to the needle, the crown being mounted on the presser foot and positioned to oppose said yieldable node-forming element.

6. In a sewing machine of the type described, the combination comprising a presser foot having an opening therethrough, a needle mounted for movement across the opening through the presser foot, and node-forming mechanism for projecting a pair of nodes of the material operated upon through the opening in the presser foot and into the path of the needle including a movably mounted support mounted for movement toward and away from the path of the needle, a rotatably mounted shaft carried by the support, two node-forming elements connected to the shaft for operation thereby, one of said nodeforming elements consisting of a segment of a disk fixedly mounted on the shaft and the other of said node-forming elements being yieldably mounted for movement transverse to the axis of the shaft, a yieldable work retaining clamp mounted to engage a node of material formed by said fixed node-forming element, and a rigid, adjustable crown mounted on the presser foot and positioned to engage a node formed by said yieldable node-forming element.

7. In a sewing machine of the type described, the combination comprising a presser foot having an opening therethrough, a needle mounted for movement across the opening through the presser foot, and node-forming mechanism for projecting a pair of nodes of the material operated upon through the opening in the presser foot and into the path of the needle including a movably mounted support mounted for movement toward and away from the path of the needle, an oscillatory shaft carried by the support, two node-forming elements connected to the shaft for operation thereby, one of said node-forming elements consisting of a segment of a disk fixedly mounted on the shaft and the other consisting of a segment of a disk freely movable transversely of the shaft, resilient means urging said latter node-forming element toward the path of the needle, a yieldable work retaining clamp positioned to engage a node of material formed by said fixedly mounted nodeforming element, and a rigid adjustable crown positioned to engage a node formed by said yieldably mounted node-forming element.

8. In a sewing machine of the type described, the combination comprising a presser foot having an opening therethrough, a needle mounted for movement across the opening through the presser foot, node-forming mechanism for projecting the material operated upon through the opening in the presser foot and into the path of the needle including two node-forming elements, an adjustable support therefor, one of said nodeforming elements being mounted in a fixed relation to the path of the needle with respect to the position of the support relative to the needle and the other node-forming element being adjustably mounted for adjustment with respect to the needle and relative to said support and said fixedly mounted node-forming element.

9. In a sewing machine of the type described, the combination comprising a presser foot having an opening therethrough, a needle mounted for movement across the opening through the presser foot, node-forming mechanism for projecting the material operated upon through the opening in the presser foot and into the path of the needie including two oscillatable node-forming elements, an adjustable support, an oscillatable shaft carried by the support, one of said node-forming elements being fixedly mounted on said shaft to maintain a fixed relation to the path of the needle with respect to the position of the support, and the other node-forming element being mounted, for adjustment relative to said support.

CHARLES W. MUELLER. 

